Headlamp for a bicycle



FIG. 1 is a front view of a headlamp for a bicycle showing our new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a perspective view thereof. 

The ornamental design for a headlamp for a bicycle, as shown. 